pacificzetecturbo

iTrader: (1)

As title, I stripped my engine down and the valves have hit the pistons only light marks on 3 but about 1mm down on No3, they are std mahle pistons so can i have pockets machined into them which would 1 remove the marks and 2 be safer in the future. Does this effect compression ratio?

Danny @ Enhanced Performance

iTrader: (3)

Have the marks just occured??or have they been there since before because its quite common to see this from people previously getting the timming wrong etc???
You will only need pocketing if your going for a bigger inlet cam etc...
If your just worried about the marks you can just de-bur them..
If you have a high lift cam then yes you can have valve cut outs with no probs and depending on valve cut out size will depend on the cr,usually with a std size cutout this will lower cr around .3 so an 8.1cr will be around 7.8cr...


cheers danny

pacificzetecturbo

iTrader: (1)

I Bought the engine second hand so dont know its history, i'm just concerned in the future with track driving etc it may hit again so thought i'd do it while i rebuild it, then either way it would be safe if i wanted to up the power and change the cams.

tabetha

You can get clip marks when revved high enough, but never any amount other than a slight mark, can have them pocketed if thinking ahead you may want hairier cam, ie BD14/15.
Shop around a LOT for prices though, one place I asked wanted £9 + vat PER cut, ie £169.20p, wasn't going to use him just wanted quote, my regular guy did them for £40 everything inc vat, but he is a tad slow at times!!
tabetha